Here is my advice to those with very limited time:
Start with your blog:
Plan ahead what your topics are going to be for the week. When you are running around town, cleaning the dishes be thinking of what you want to write. Carry a notepad and jot ideas down throughout the day. You can write drafts, and also set the posts to a future date. Making a plan can help cut the time down.
Using Twitter from a distance:
You can step Twitter up so your shop, blog and flickr Rss feeds post directly to your channel. Really anything that has a RSS feed can be linked. So in all reality you don't even have to post on Twitter, but you will be missing out on the important social side to it. The social side really only take a few mins a day of checking and commenting on others posts you find interesting.
here is the link to TwitterFeed... this is where you can link your RSS feed to your Twitter channel!
Facebook, and other sites:
What i like to do is to promote what i have already done, like link to the blog post i just posted or show off an item i just listed. On facebook you can promote your blog/item in all the groups you have joined.. this will only take a matter of mins.
For Nings like IndiePublic and We love etsy you can directly post the html code in a blog on your page. I do this after almost all my blog posts ( if i remember).
Please share your tips for streamlining your promo process.. here on the blog and on this Etsy thread HERE